Is there any logic to ISO numbers?

ISO 9001 is probably the most well recognized ISO number in the world. ISO/TC292 has published several different standards with various numbers including ISO 22301 and ISO 28000. One question that comes to mind is whether the number mean anything and if there is any logic how ISO produce its standards?

In order to sort things out we contacted Stefan Tangen (Sweden), the convenor of the ISO/TC 292 Communication Group who was happy to explain.

Is there any system on how ISO selects its numbers?

No, normally ISO uses random numbers for the publications. But there are rules of course. For example, an ISO number can only be used once. Its important to keep in mind that ISO has already published about 20.000 documents so it would be impossible to sort out some kind of logic for all documents.

But it appears to be some kind of logic. The ISO 9000 series have much in common with ISO 14000?

Yes, ISO/TC 176 responsible for the ISO 9000 series realized early the marketing value of using recognizable ISO numbers in a logical system and many other committees especially involved in Management System Standards development have made similar series. In the ISO 9000 series, "00" is a vocabulary document, "01" represent a certifiable MSS with requirements and "04" a guidance document to the "01". Even though there are other series that follows the same logic, it can not be seen as ISO praxis since there are many standards that do not follow such an approach. ISO/TC 292 is for example responsible for three certifiable MSS with the numbers: ISO 22301, ISO 28000 and ISO 18788. It can also be quite difficult to follow a logical system considering that many numbers have already been used. For example, when the guidance document was developed to ISO 22301 we wanted to use the "04" logic but discovered ISO 22304 already in use by another committee so we had to go with ISO 22313.

So how do you deal with this in ISO/TC 292?

The Communication Group in ISO/TC 292 got the assignment after our first plenary meeting to find a solution for TC 292 and this work was abit like the old expression "square peg in a round hole". Considering that it would take numerous of years to change everything to a new system we decided to stick with what we have and slowly move towards a consistent system. All titles on published documents will from here on start with the introductory element "Security and resilience". This also means that the word "Societal security" will disappear once a document has been revised. We will continue with the three number series ISO 22300, ISO 28000 and ISO 34000 and over time the use of random numbers will be gone.

Can we expect new numbers to appear?

We cant predict the future but we have agreed that if needed we might add additional series if there are strong reasons for that.

Numbers randomly used by other committees before ISO/TC 223 started with the ISO 22300 series.